Mercury-vapor jet pump



Aug. 114, 11923, wsmw H. M.'C.-UNGLAUBE MERCURY VAPOR TET PUMP Filed March 10, 1923 2 Sheets-Shet l Aug. 114, 11923. 31,465,,(186) H. M. C. UNGLAUBE MERCURY VAPOR JET PUMP Filed March 10 1923 2 Sheets-Sheet, 2

. Patented Aug. 114, 11223.

Lltiitllltl entree stares PATENT orrtce.

HERBERT MARTIN CARL UNGLAUBE, HAMBURG, GERMANY, ASSIGNOR TO THE FIRM 01 DATE LABORATORIUMS- UNI) INDUSTRIE-BEDARF G. M. B. EL, F

HAMBURG, GERMANY.

MERCURY-VAPOR JET rumor.

Application filed March 10, 1923. Serial No. 624,139.

To all whom it may concern:

Be it known that I, HERBERT MARTIN CARL UNGLAUBE, citizen of Germany, residing at Hamburg, Goldbeckufer 29, Germany,

have invented certain new and useful Improvements in a Mercury-Vapor Jet Plunp (for which I have filed applications in Germany, D. 4:135!) I/27 d, and D. 1360 T/27 d, both on March 6, 1922), of which the followloing is a specification.

This invention relates to a mercury vacuum pump or mercury vapor ejector in which by the aid'of mercury vapors an ejector operates to cause evacuation and which is distinguished from the known ejectors of this kind by highest efficiency of the pump and greatest economy in the consume of vapor, and moreover does away with some drawbacks of the pumps or ejectors known heretofore inasmuch as the annular space surrounding the jet nozzle, which conducts the air or gas to be pumped, is not clogged by the condensed mercury substance owing to the surface tension, and moreover the electric high tension discharges that might occur are diverted or led away, so as to render them inofiensive.

In the drawing two modes of construction are illustrated.

Fig. 1 is a longitudinal section of the mercury-vapor-jet-pump for medial vacuum, and

Fig. 2 a longitudinal section through the pump for high vacuum.

Both pumps are preferably made of glass.

In the construction shown in Fig. 1 the mercury bowl 1 serving for producing the mercury vapor by heat is arranged at the lowest end of the tube 2, which may be preferably isolated in the usual manner, and communicates with a pipe 3 having at its end the jet nozzle 4. The latter has a contraction similar to the Laval nozzle, and expands conically towards the outer end. The

jet nozzle opens out into the lower pearshaped conduit 5, the lower end of which is connected with the mercury bowl 1 by the pipe 6. This conduit, which near the jet nozzle 4: is cylindrical, has a contraction 61,

thus approaching close to the outer surface of the jet nozzle 4. The annular space formed between the conduit and the nozzle expands towards the discharge end of the nozzle a, its conicity of the conduit 5 being greater at this place than that of the nozzle. he gas to be sucked by the pipe 7 will be conducted to the trumpet-like annular space. The conduit 5 is connected with the inner wall of the cooling vessel 8 as shown in such manner that the latter forms a perfectlfy closed chamber into which the water is ed by the pipe 9, and from which the cooling water is drawn away by the pipe 10.

A pipe 11 is fastened to the pipe 6 by melting, and enables to uphold a vacuum or partial vacuum in the conduit 5, for instance by means of a water ejector.

The pump, which is particularly intended for medial vacuum, has the advantage, that the annular space surrounding the jet nozzle 4 will never be clogged by condensed mercury substances, The mercury vapor fed from the tube 2 by the pipe 3 into the jet nozzle 4 expands within the jet nozzle 4 in such mannef that an optimum of the jet speed is attained, so as to avoid the formation of whirls at the outlet opening of the nozzle 4 to a great extent. When now condensed mercury enters the annular space about the nozzle 4 this would be harmless, since the mercury would run down the walls of the cylindrical part of the conduit 5, the nozzle having a downward direction, and the annular space surrounding it, expanding downwardly. The surface tension of the condensed mercury together with its weight has the effect that any'film of mercury substance within the annular space would tear and the mercury would run down in the form of drops.

The modification shown in Fig. 2, which represents a pump or ejector for high vacuum, answers the same purpose, but beyond this has other advantages. Here also the bowl 12 to be heated and containing the mercury, is mounted on the lower end of a tube 13, which feeds the mercury vapor to the pump proper, and maybe isolated in any known manner. The tube 13 communicates with a vertical pipe 14 arranged at the upper end of the casing. Within this pipe 14 there is a second pipe 15. concentrically arranged to form an annular space, which is in communication with the nozzle 16. This nozzle 16 is annular in all horizontal sections, and is bound at the inner side by a spherical or otherwise shaped dish 17 forming the prolongation of the pipe 15, and. at

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the outer side by the wall of the antevacuum vessel 18 forming a prolongation of the pipe 14. These boundary surfaces of the nozzle 16 are at a constant distance from one an- 5 other approximately throughout. The diameter, however, of the annular jet nozzle 16 owing to the dish-shape increases gradually towards the discharge opening. The mercury vapors coming from the tube 13 enter the nozzle 16 about its centre, and flow radially towards the outside thus expanding owing to the increased diameter almost up to theante-vacuum. Owing to the sharp bend of the dishes forming the nozzle 16 shortly 15 before the discharge opening, the jet of vapor rushing out will have the shape of a cylinder or of a truncated cone.

Concentric with the jet nozzle 16 there is .the annular space 19 conducting the gas to 20 be pumped, which space is bound on one side by the inner wall of the dish 17, and on the other side by the outer wall of the cooling vessel 20 arranged within. The pipe feeds the gas to be pumped to the annular space 19, and thus to its annular pump opening. The pipe 21 conducts the vapors from the vessel 18 to the ante-vacuum pump. The mercury vapor, discharged by the nozzle 16, is condensed on the outer wall of the cooling vessel 20, and by the pipe 22 is again conducted to the bowl12. Since the jet of vapors expands before leaving the nozzle 16 approximately up to the antevacuum, and its surface being increased to a maximum without essentially descreasing the jet speed, an

optimum pump speed and the highest economy' of vapor consume will be the result of the improvements. j

The cooling vessel 20 carries on top a tubu- 40 lar prolongation 23, which reaches beyond the place of attachment of the tube 13, and carries at its top a vacuum tight metal conductor 24, wire or the like, the object of which is to divert or lead away electric high tension discharges, which, as is well known, are caused to a great extent by condensation of mercury vapors on the high vacuum side of the pump past the cool water vessel to the earth; To facilitate this diversion the ver- 9 tical pipe 25, which preferably conducts the cooling water to the cooling vessel 20, is led close up to the metal wire 24. The draining of the water is carried out by the pipe 26. By the means described above it will be avoided that the walls are broken by the 'hi h tension discharges.

claim:

- 1. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, 69 an outwardly flaring jet nozzle directed 2. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, an annular jet nozzle directed downwardly, a cooling chamber and a conduit for the gas ejected and discharged by the nozzle, an annular flaring portion concentric with the nozzle and communicating with the gas feed pipe, and increasin in diameter towards the mouth of the nozz e.

3. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, an annular jet nozzle at the end of the mercury vapor feed pipe and adapted to suck gas from the gas feed pipe, a conduit for the gas discharged by the nozzle, a cooling chamber surrounded by the annular jet nozzle, which increases in diameter towards the mouth end and is so shaped that the jet discharged approximately has the shape of a cylinder.

4. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, a dish at the end of the gas feed pipe and a dish at the end of the mercury vapor feed ipe the two dishes being arranged at a distance apart to form a nozzle increasing in diameter towards the outer rim and bent near the rim to discharge the vapors in the shape approximately of a cylinder.

5. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, an annular jet nozzle, at the end of the mercury vapor feed pipe and adapted to suck gas from the gas feed pipe, a conduit for the gas discharged by the nozzle, a cooling chamber surrounded by the annular jet nozzle, which increases in diameter towards the mouth end and is so shaped that the jet discharged approximately has the shape of a cylinder, a metal conductor passing from the cooling chamber through its walls into the said gas feed pipe, and adapted to divert electric high tension discharges away.

6. A mercury vapor jet pump comprising a mercury vapor feed pipe, a gas feed pipe, a cooling chamber, and an outwardly flaring dished portion at the end of the vapor feed pipe, said portion surrounding the said cooling chamber, whereby mercury vapor dis charging ,from the vapor feed pipe sucks gas from the gas feed pipe.

In testimony whereof I have signed my name to this specification.

HERBERT MARTIN CARL UNGLAUBE. 

